Methods of Cementing in Subterranean Formations

ABSTRACT

Methods of cementing are provided including a method comprising: a method of cementing in a well bore comprising providing a storable cement composition; placing the storable cement composition in an annulus in a reverse-circulation direction using cementing equipment supported by a trailer, wherein the annulus is formed by an outer surface of a casing in the well bore and an inner wall of the well bore; and allowing the storable cement composition to set in the annulus. In some embodiments, the storable cement composition may comprise a hydraulic cement, an aqueous fluid, and a set retarder. In some embodiments, a storable cement composition may be transported to the well bore using a trailer connected to a towing vehicle. Additional methods are also provided.

BACKGROUND

The present invention relates to methods of cementing for use in industrial, oilfield, and/or subterranean operations. More particularly, the present invention generally relates to methods of cementing involving storable cement compositions and/or reverse cementing methods.

Hydraulic cement compositions are commonly utilized in subterranean operations, particularly subterranean well completion and remedial operations. For example, hydraulic cement compositions are used in primary cementing operations whereby pipe strings, such as casings and liners, are cemented in well bores. In performing primary cementing, hydraulic cement compositions commonly are pumped into an annular space between the walls of a well bore and the exterior surface of a pipe string disposed therein. The cement composition is permitted to set in the annular space, thereby forming therein an annular sheath of hardened, substantially impermeable cement that substantially supports and positions the pipe string in the well bore, and that bonds the exterior surface of the pipe string to the walls of the well bore. Conventionally, two pumping methods have been used to place the cement composition in the annulus. First, the cement composition may be pumped down the inner diameter of the pipe string, out through a casing shoe and/or circulation valve at the bottom of the pipe string, and up through the annulus to a desired location. The direction in which the cement composition is pumped in this first method is generally referred to as a conventional-circulation direction. Second, the cement composition may be pumped directly down the annulus, thereby displacing any well fluids present in the annulus by pushing them through the casing shoe and up the inner diameter of the pipe string. The direction in which the cement composition is pumped in this second method is generally called a reverse-circulation direction (“reverse cementing”).

Reverse circulating the cement composition into the annulus may be useful in a variety of circumstances. For example, when a well bore penetrates a subterranean formation that comprises one or more weak portions, reverse-circulation cementing can reduce the pressure exerted against these weak portions during placement. A reduction in pressure can help prevent the loss of the cement composition to the formation, which, if this loss occurs, may result in incomplete annular fill of the annulus with the cement composition, need for extra cement being used, and/or require remedial operations to fill the annulus. With reverse cementing, cementing pressures are much lower than those experienced with conventional methods and cement introduced in the annulus free-falls down the annulus, producing little or no pressure on the formation. Furthermore, when a reverse cementing method is used, less fluid is required to be handled at the surface and cement set retarders may be utilized more efficiently.

Storable cement compositions are often utilized in circumstances where an operator finds it desirable to prepare a volume of a cement composition that remains in a pumpable state for a long period of time (e.g., for about two weeks or more), and that can be selectively activated to set into a hard mass at a desired time. For example, in circumstances where very large volumes of cement are utilized (such as in offshore platform grouting), the equipment required for mixing and pumping the requisite large volumes of cement composition may be very expensive, and may be difficult to assemble at the desired location. The storage of the requisite amount of dry cement prior to use may be another problem. As another example, the use of a storable cement composition may also be desirable in circumstances where a relatively small volume of cement composition is used, such as a small construction job, for example, or a plugging and squeezing operation performed in the petroleum industry, for instance. In such circumstances, the cost to transport the cement composition to a job site, and to mix and pump it on location may be undesirable relative to the revenue generated from performing the cementing operation. Storable cement compositions may be useful in circumstances such as those described above, as they can be prepared at a convenient location, then transported to and stored at a job site until use. At a desired time, the storable cement composition may be mixed with a set activating agent; the resulting mixture may then be placed into a desired location (e.g., into a subterranean formation) and permitted to set therein. In some formulations, an excessive amount of set-activating agents have been injected into the set-delayed cement compositions, thereby “overactivating” the cement composition, after which a retarder is then added to the cement composition, in an attempt to fine-tune the eventual set time of the cement composition.

As previously stated, the equipment required for cementing operations, including conventional cementing operations and reverse cementing, may be very expensive and difficult to assemble at the desired location. In addition, this equipment must generally be transported to the worksite via one or more tractor-trailers. Since the operation of a tractor-trailer is highly regulated, the cementing operations are also controlled by Department of Transportation (“D.O.T.”) regulations. These regulations cover a number of variables, including the number of hours that a person may work in a given period, the number of hours a driver may drive, and the skill level of the drivers. Furthermore, tractor-trailers are also limited by terrain, and may not be able to enter certain worksites without suitable roads first being built, which may be a costly endeavor.

SUMMARY

The present invention relates to methods of cementing for use in industrial, oilfield, and/or subterranean operations. More particularly, the present invention generally relates to methods of cementing involving storable cement compositions, reverse cementing methods and/or cementing equipment supported by a trailer.

In one embodiment, the present invention provides a method of cementing in a well bore comprising providing a storable cement composition; placing the storable cement composition in an annulus in a reverse-circulation direction using cementing equipment supported by a trailer, wherein the annulus is formed by an outer surface of a casing in the well bore and an inner wall of the well bore; and allowing the storable cement composition to set in the annulus.

In another embodiment, the present invention provides a method of cementing in a well bore comprising providing a storable cement composition comprising a hydraulic cement, an aqueous fluid, and a set retarder; placing the storable cement composition in an annulus in a reverse-circulation direction using cementing equipment supported by a trailer, wherein the annulus is formed by an outer surface of a casing in the well bore and an inner wall of the well bore; and allowing the storable cement composition to set in the annulus.

In another embodiment, the present invention provides a method of cementing in a well bore comprising providing a storable cement composition; transporting the storable cement composition to the well bore using a trailer connected to a towing vehicle; placing the storable cement composition in an annulus in a reverse-circulation direction using cementing equipment supported by the trailer, wherein the annulus is formed by an outer surface of a casing in the well bore and an inner wall of the well bore; and allowing the storable cement composition to set in the annulus.

The features and advantages of the present invention will be readily apparent to those skilled in the art. While numerous changes may be made by those skilled in the art, such changes are within the spirit of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention relates to methods of cementing for use in industrial, oilfield, and/or subterranean operations. More particularly, the present invention generally relates to methods of cementing involving storable cement compositions, reverse cementing methods and/or cementing equipment supported by a trailer.

The methods of the present invention generally comprise providing a storable cement composition; placing the storable cement composition in an annulus in a reverse-circulation direction using cementing equipment supported by a trailer, wherein the annulus is formed by an outer surface of a casing in the well bore and an inner wall of the well bore; and allowing the storable cement composition to set in the annulus.

In general, any storable cement composition suitable for use in industrial, oilfield, and/or subterranean operations may be suitable for use in the present invention. Suitable storable cement compositions generally comprise cement compositions capable of being retained in a pumpable state for an extended period of time prior to being set into a hardened mass. In some embodiments, the storable cement compositions suitable for use in the methods of the present invention may be capable of being stored for at least two weeks and in some instances, several months. In some embodiments, storable cement compositions suitable for use in the methods of the present invention may comprise a base fluid and a cement. Furthermore, in some embodiments, storable cement compositions suitable for use in the methods of the present invention may comprise a set retarder and/or an activating agent.

The storable cement compositions suitable for use in the methods of the present invention comprise a base fluid. Examples of suitable base fluids include aqueous fluids, such as fresh water, saltwater, brine, seawater, and/or any other aqueous fluid that does not adversely react with the other components used in accordance with this invention or with the subterranean formation, and non-aqueous fluids, such one or more organic liquids, such as hydrocarbons (e.g., kerosene, xylene, toluene, or diesel), oils (e.g., mineral oils or synthetic oils), esters, and the like.

The storable cement compositions suitable for use in the methods of the present invention comprise a cement. Examples of suitable cements include, but are not limited to, hydraulic cement, Portland cement, pozzolanic cement, gypsum cement, calcium phosphate cement, high alumina content cement, silica cement, high alkalinity cement, and combinations thereof.

Set retarders suitable for use in a storable cement composition may include any set retarder known in the art. Examples of suitable set retarders include glucoheptonates, such as sodium glucoheptonate, calcium glucoheptonate and magnesium glucoheptonate; lignin sulfonates, such as sodium lignosulfonate and calcium sodium lignosulfonate; gluconates, such as sodium gluconate, calcium gluconate and calcium sodium gluconate; phosphonates, such as the sodium salt of EDTA phosphonic acid; sugars, such as sucrose; hydroxycarboxylic acids, such as citric acid; and the like, boric acid, and combinations thereof.

An activating agent may be added to the storable cement compositions to effectuate the hardening of the storable cement composition. Examples of suitable activating agents may include, but are not limited to, solutions of Group IA and IIA hydroxides, such as sodium hydroxide, magnesium hydroxide and calcium hydroxide; sulfates, such as sodium sulfate; aluminates, such as sodium aluminate and potassium aluminate; carbonates, such as sodium carbonate and silicates; calcium chloride, paraformaldehyde, and combinations thereof.

Examples of storable cement compositions that may be suitable for use in the methods of the present invention include, but are not limited to, those described in U.S. Pat. Nos. 4,676,832; 5,348,584; 5,547,506; 5,585,333; 6,173,778; 6,832,652, and 6,907,928; U.S. Patent Application No. 2005/0166803; and U.S. patent application Ser. No. 11/428,771, the entire relevant disclosures of which are herein incorporated by reference.

Optionally, other additional additives may be added to the storable cement compositions suitable for use in the present invention as deemed appropriate by one skilled in the art, with the benefit of this disclosure. Examples of such additives include, but are not limited to, accelerators, weight reducing additives, heavyweight additives, lost circulation materials, filtration control additives, foaming agents, dispersants, defoamers, salts, vitrified shale, fly ash, fiber, strength retrogression additives, expanding additives, yield stress reducing agents, surfactants, dehydrating agents, viscosifiers, suspension agents, fibers, salts, formation conditioning agents, and combinations thereof. One of ordinary skill in the art, with the benefit of this disclosure, will be able to recognize where a particular additive is suitable for a particular application.

In some embodiments of the present invention, a suitable storable cement composition may be placed into an annulus in a well bore in a reverse-circulation direction. In these embodiments, a suitable storable cement composition is placed directly into an annulus formed by the outer surface of the casing and an inner wall of the well bore. While one of ordinary skill in the art would be aware of various methods of cementing in a reverse-circulation direction, examples of particular methods of reverse-circulation cementing and equipment used in these methods are described in U.S. Patent Application Nos. 2006/0102350 and 2006/0086499, which are herein incorporated by reference.

In some embodiments of the present invention, a suitable storable cement composition may be placed into an annulus in a well bore using cementing equipment supported by a trailer. Additionally, in some embodiments, a storable cement composition suitable for use in the methods of the present invention may be prepared by using cementing equipment supported by a trailer. One of the many advantages of using cementing equipment supported by a trailer to prepare a storable cement composition and/or to place a storable cement composition in a subterranean formation is that the cementing equipment supported by the trailer may be transported to the worksite via a towing vehicle that is not subject to certain regulations imposed by the Department of Transportation (“D.O.T.”).

In those embodiments where a trailer is used, the trailer may be connectable to a towing a vehicle, such that the movement of the towing vehicle may result in the movement of the trailer. An example of a suitable towing vehicle may include a self-propelled vehicle having a gross vehicle weight rating (“GVWR”) or gross vehicle weight (“GVW”) of less than 10,001 pounds (4,536 kilograms). In some embodiments, the combined towing vehicle and trailer may have a combination GVWR or combination GVW of less than 26,001 pounds (11,794 kilograms). Alternatively, the GVWR of the towing vehicle and/or trailer may meet “Bridge” and “Frost” laws of the United States and/or Canada. Alternatively, the axles of the towing vehicle and/or trailer may be rated such that the GVW can traverse roads with minimal load supporting capacities.

Examples of cementing equipment that may be supported by a trailer include, but are not limited to, a bulk material container, a bulk material conveyor, a package holder, a package handler, a material measuring device, a holding tank, a holding tank conveyor, a mixing device, a mixing pump, a mixing manifold or manifold system, a mixing measuring device, a delivery pump, a pumping manifold, a pumping measuring device, a delivery pump, etc. In addition, examples of suitable towing vehicles, trailers, and servicing/cementing equipment is disclosed in U.S. patent application Ser. No. 11/675,812, the entire disclosure of which is herein incorporated by reference.

One example of a method of the present invention is a method of cementing in a well bore comprising providing a storable cement composition; placing the storable cement composition in an annulus in a reverse-circulation direction using cementing equipment supported by a trailer, wherein the annulus is formed by an outer surface of a casing in the well bore and an inner wall of the well bore; and allowing the storable cement composition to set in the annulus.

Another example of a method of the present invention is a method of cementing in a well bore comprising providing a storable cement composition comprising a hydraulic cement, an aqueous fluid, and a set retarder; placing the storable cement composition in an annulus in a reverse-circulation direction using cementing equipment supported by a trailer, wherein the annulus is formed by an outer surface of a casing in the well bore and an inner wall of the well bore; and allowing the storable cement composition to set in the annulus.

Yet another example of a method of the present invention is a method of cementing in a well bore comprising providing a storable cement composition; transporting the storable cement composition to the well bore using a trailer connected to a towing vehicle; placing the storable cement composition in an annulus in a reverse-circulation direction using cementing equipment supported by the trailer, wherein the annulus is formed by an outer surface of a casing in the well bore and an inner wall of the well bore; and allowing the storable cement composition to set in the annulus.

Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood as referring to the power set (the set of all subsets) of the respective range of values, and set forth every range encompassed within the broader range of values. Moreover, the indefinite articles “a” or “an”, as used in the claims, are defined herein to mean one or more than one of the element that it introduces. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. 

1. A method of cementing in a well bore comprising: providing a storable cement composition; placing the storable cement composition in an annulus in a reverse-circulation direction using cementing equipment supported by a trailer, wherein the annulus is formed by an outer surface of a casing in the well bore and an inner wall of the well bore; and allowing the storable cement composition to set in the annulus.
 2. The method of claim 1 wherein the trailer is moved by a towing vehicle, wherein the combination gross weight rating or combination gross vehicle weight of the trailer and the towing vehicle is less than 26,001 pounds.
 3. The method of claim 1 wherein the cementing equipment comprises at least one selected from the group consisting of a bulk material container, a package holder, a bulk material conveyor, a package handler, a measuring device, and a combination thereof.
 4. The method of claim 1 wherein the storable cement composition comprises a hydraulic cement, water, and a set retarder.
 5. The method of claim 1 further comprising activating the storable cement composition.
 6. The method of claim 5 wherein activating the storable cement composition comprises adding an activating agent to the storable cement composition using the cementing equipment supported by the trailer.
 7. The method of claim 6 wherein the activating agent comprises at least one activating agent selected from the group consisting of sodium hydroxide, magnesium hydroxide, calcium hydroxide, sodium sulfate, sodium aluminate, potassium aluminate, sodium carbonate, silicates, calcium chloride, paraformaldehyde and combinations thereof.
 8. A method of cementing in a well bore comprising: providing a storable cement composition comprising a hydraulic cement, an aqueous fluid, and a set retarder; placing the storable cement composition in an annulus in a reverse-circulation direction using cementing equipment supported by a trailer, wherein the annulus is formed by an outer surface of a casing in the well bore and an inner wall of the well bore; and allowing the storable cement composition to set in the annulus.
 9. The method of claim 8 wherein the cementing equipment comprises at least one selected from the group consisting of a bulk material container, a package holder, a bulk material conveyor, a package handler, a measuring device, and a combination thereof.
 10. The method of claim 8 wherein the trailer is moved by a towing vehicle, wherein the combination gross weight rating or combination gross vehicle weight of the trailer and the towing vehicle is less than 26,001 pounds.
 11. (canceled)
 12. The method of claim 8 further comprising activating the storable cement composition.
 13. The method of claim 12 wherein activating the storable cement composition comprises adding an activating agent to the storable cement composition using the cementing equipment supported by the trailer.
 14. The method of claim 13 wherein the activating agent comprises at least one activating agent selected from the group consisting of sodium hydroxide, magnesium hydroxide, calcium hydroxide, sodium sulfate, sodium aluminate, potassium aluminate, sodium carbonate, silicates, calcium chloride, paraformaldehyde and combinations thereof.
 15. A method of cementing in a well bore comprising: providing a storable cement composition; transporting the storable cement composition to the well bore using a trailer connected to a towing vehicle, wherein the combination gross weight rating or combination gross vehicle weight of the trailer and the towing vehicle is less than 26,001 pounds; placing the storable cement composition in an annulus in a reverse-circulation direction using cementing equipment supported by the trailer, wherein the annulus is formed by an outer surface of a casing in the well bore and an inner wall of the well bore; and allowing the storable cement composition to set in the annulus.
 16. The method of claim 15 wherein the cementing equipment comprises at least one selected from the group consisting of a bulk material container, a package holder, a bulk material conveyor, a package handler, a measuring device, and a combination thereof.
 17. The method of claim 15 further comprising activating the storable cement composition.
 18. The method of claim 17 wherein activating the storable cement composition comprises adding an activating agent to the storable cement composition using cementing equipment supported by a trailer.
 19. The method of claim 18 wherein the activating agent comprises at least one activating agent selected from the group consisting of sodium hydroxide, magnesium hydroxide, calcium hydroxide, sodium sulfate, sodium aluminate, potassium aluminate, sodium carbonate, silicates, calcium chloride, paraformaldehyde and combinations thereof
 20. The method of claim 15 wherein providing the storable cement composition comprises mixing a cement composition using cementing equipment supported by a trailer.
 21. The method of claim 15 wherein the storable cement composition comprises a hydraulic cement, water, and a set retarder. 